Projects are needed to be produced in order to developing the cities and tourist destinations. Oneof the suppliers of these projects is development agencies. In this study, the city where theİstanbul development Agency is located, is examined for the enhancing the tourism potential, thesustainability of the contribution to the branding process and the importance for the developmentagencies of destinations. Also attempt to bring harmony between the results they achieve withthe goals of the agency. İstanbul Development Agency has been selected as a case study to realizethe objectives of the research. In this study, the Semi-structure interview technique, which isqualitative research method, is used. For this purpose, semi-structured survey form applied. Inthe descriptive analysis research, İstanbul Development Agency, contributes to increasing thetourism potential of the city, sustainable and branding the city. It is determined that, especiallycooperating with the other companies, in the area, brings important innovations to branding thecity and supporting lots of project, relating the subject.